The overall goal of this grant is to experimentally test the hypothesis that the pubertal period represents a "window of heightened sensitivity" to external perturbations that may have long-term health consequences. Specifically, this project is determining whether monkeys going through the pubertal transition are more sensitive to the various health consequences of social stress and moderately vigorous exercise training than monkeys in the early post-pubertal period. The health consequences that are being monitored are (1) reproductive function, including menstrual cyclicity and reproductive hormone secretion, (2) bone structure and growth, (3) body fat distribution, (4) serum lipid content, (5) glucose tolerance, (6) immune function, (7) susceptibility to viral infection, and (8) cardiovascular function, including resting heart rate, heart rate response to stress, and echocardiographic measurements. These parameters are being studied because they are known to be influenced by social stress and exercise and they are all thought to be affected by reproductive steroid hormone levels. Thus, they are likely to be affected by the pubertal transition as well as by the external perturbations that are being studied.